“Aguilon was one of the first of a long line of distinguished Jesuit writers on optics. His treatise has acquired a great deal of attention because of its seven engravings (by Theodore Galle) after drawings by [Peter Paul] Rubens. It is not so well known that Aguilon’s color theory and his prescriptions for the mixing of colors were actually used by Rubens in his paintings” (Ashworth in Jesuit Science in the age of Galileo, no. 8).

The work’s “organization into three sections was determined by the manner in which the eye perceives objects (directly, by reflection on polished surfaces, and by refraction through transparent bodies) … Aguilon treated, successively, the eye, the object, and the nature of vision; the optic ray and horopter; the general ideas that make possible the knowledge of objects; errors in perception; luminous and opaque bodies; and projections.

“The sixth book, on orthographic, stereographic, and scenographic projections, remains important in the history of science. It accounts for a third of the treatise and was meant for the use of astronomers, cosmographers, architects, military leaders, navigators, painters, and engravers. It places particular emphasis on stereographic projection—a type of projection, used by Ptolemy, in which the portion of the sphere to be represented is projected from the pole onto the plane of the equatorial circle.

“The balance of the treatise is of interest for the history of optics: description of the eye; controversies on the nature of light and its action; the application of mathematics to optics; the analysis of the concepts of distance, quantity, shape, place, position, continuity, discontinuity, movement, rest, transparency, opacity, shadow, light, resemblance, beauty, and deformity; and explanation of the various errors of perception linked to distance, size, position, shape, place, number, movement, rest, transparency, and opacity.

“Book 5, in spite of an Aristotelian concept of light, studies the propagation of light, the limit of its action, the phenomena produced by the combinations of light sources, and the production of shadows. Aguilon proposes an experimental apparatus, drawn by Rubens, that made it possible to study the variations of intensity according to variations in distance and to compare lights of different intensities. This attempt to apply mathematics to the intensity of light was continued by Mersenne, then by Claude Milliet de Chales, and resulted in Bouguer’s photometer.” (J.E. Morère in DSB).

For a full discussion of this book, and Ruben’s role in his illustrations for the text, see Martin Kemp, The Science of Art, pp. 101-104.

Folio: 344 x 220 mm, pp. [xlviii] 684 [44], contemporary green inverse calf with raised bands and gilt title label to spine, edges sprinkled in red. Allegorical engraved title and six engraved headpieces by Theodore Galle after Peter Paul Rubens. Some browning throughout, as usual for this book, in all a very good copy.

“Aguilon was one of the first of a long line of distinguished Jesuit writers on optics. His treatise has acquired a great deal of attention because of its seven engravings (by Theodore Galle) after drawings by [Peter Paul] Rubens. It is not so well known that Aguilon’s color theory and his prescriptions for the mixing of colors were actually used by Rubens in his paintings” (Ashworth in Jesuit Science in the age of Galileo, no. 8).

The work’s “organization into three sections was determined by the manner in which the eye perceives objects (directly, by reflection on polished surfaces, and by refraction through transparent bodies) … Aguilon treated, successively, the eye, the object, and the nature of vision; the optic ray and horopter; the general ideas that make possible the knowledge of objects; errors in perception; luminous and opaque bodies; and projections.

“The sixth book, on orthographic, stereographic, and scenographic projections, remains important in the history of science. It accounts for a third of the treatise and was meant for the use of astronomers, cosmographers, architects, military leaders, navigators, painters, and engravers. It places particular emphasis on stereographic projection—a type of projection, used by Ptolemy, in which the portion of the sphere to be represented is projected from the pole onto the plane of the equatorial circle.

“The balance of the treatise is of interest for the history of optics: description of the eye; controversies on the nature of light and its action; the application of mathematics to optics; the analysis of the concepts of distance, quantity, shape, place, position, continuity, discontinuity, movement, rest, transparency, opacity, shadow, light, resemblance, beauty, and deformity; and explanation of the various errors of perception linked to distance, size, position, shape, place, number, movement, rest, transparency, and opacity.

“Book 5, in spite of an Aristotelian concept of light, studies the propagation of light, the limit of its action, the phenomena produced by the combinations of light sources, and the production of shadows. Aguilon proposes an experimental apparatus, drawn by Rubens, that made it possible to study the variations of intensity according to variations in distance and to compare lights of different intensities. This attempt to apply mathematics to the intensity of light was continued by Mersenne, then by Claude Milliet de Chales, and resulted in Bouguer’s photometer.” (J.E. Morère in DSB).

For a full discussion of this book, and Ruben’s role in his illustrations for the text, see Martin Kemp, The Science of Art, pp. 101-104.

Folio: 344 x 220 mm, pp. [xlviii] 684 [44], contemporary green inverse calf with raised bands and gilt title label to spine, edges sprinkled in red. Allegorical engraved title and six engraved headpieces by Theodore Galle after Peter Paul Rubens. Some browning throughout, as usual for this book, in all a very good copy.